Field of the Invention
The present invention relates to a platform drug delivery system and, more specifically, to a novel method of improving the delivery of low solubility pharmaceuticals utilizing crystal engineering and Theanine dissolution resulting in enhanced bioactivity, dissolution rate, and solid state stability.
Background of the Invention
There are clear unmet needs in the pharmaceutical industry and medical community to improve drug delivery and improve the clinical status of the patient more rapidly. Therapeutic compounds are most stable in a crystalline form, but can display slow dissolution rates resulting in reduced bioavailability of the active pharmaceutical ingredient, thereby slowing absorption. The ongoing interest in modification of drug substances whose physical properties are less than desirable has led to significant study of issues associated with polymorphism and solvatomorphism. More recently, it has been recognized that many substances may cocrystallize in a single continuous lattice structure, leading pharmaceutical scientists into new areas of crystal engineering. Cocrystals are mixed crystals where the cocrystal is a structurally homogeneous crystalline material that has been formed from discrete neutral molecular species that are solids at ambient temperatures.
Cocrystals represent novel forms of drug substances that would be suitable for incorporation in pharmaceutical solid dosage forms, and should enable formulation scientists to overcome a variety of problems that are encountered during development of traditional formulations. One could consider cocrystals as being an alternative to polymorphs, solvatomorphs, and salts, and cocrystals represent a different approach to solve problems related to dissolution, crystallinity, hygroscopicity, etc. The most important improvement that might accompany the formation of a cocrystal would be an enhancement in the solubility of the drug substance, or at least a faster degree of dissolution.
The recently disclosed cocrystal system formed by aspirin (acetylsalicylic acid) and theanine (5-N-ethyl-glutamine) amply demonstrates the potential advantages that can be achieved. Although several new pharmaceutical cocrystals have been advanced into preclinical and clinical studies, further advances are needed to address the increasing complexity of new drug candidates. Unfortunately, it is not yet possible to predict whether two substances will cocrystallize or not, and therefore cocrystal screening studies are largely empirical in nature.
The cocrystal of Theanine is a general form which can be translated to other ion containing drugs. This makes it very attractive to the pharmaceutical industry for the following reasons: drug companies want to know that there are pipeline possibilities for other new products, creates a defensive measure for an existing branded pharmaceutical against generic introduction, and expands indications for a low solubility branded pharmaceutical.
Crystallization and Theanine dissolution of low solubility pharmaceuticals is paramount in the treatment of patients presenting with a wide variety of emergent conditions where improved drug delivery would be of benefit.
The harmful effect of glutamate upon the CNS were first observed in 1954 by T. Hayashi, a Japanese scientist who noted that direct application of glutamate to the CNS caused seizure activity (Wikipedia, “Excitotoxicity”. March, 2012. http://en.wikipedia.org/wiki/Excitotoxicity). Excitotoxicity is the pathological process by which nerve cells are damaged and killed by excessive stimulation by neurotransmitters such as glutamate and similar substances. This occurs when receptors for the excitatory neurotransmitter glutamate (glutamate receptors) such as the NMDA receptor (N-methyl-D-aspartate receptor) and AMPA receptor (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor) are overactivated by glutamatergic storm (Wikipedia, “Excitotoxicity” March, 2012 http://en.wikipedia.org/wiki/Excitotoxicity). Excitotoxins like NMDA and kainic acid which bind to these receptors, as well as pathologically high levels of glutamate, can cause excitotoxicity by allowing high levels of calcium ions (Ca2+) to enter the cell (Manev, H.; Favaron, M.; Guidotti, A.; and Costa, E., Delayed increase of Ca2+ influx elicited by glutamate: role in neuronal death. Molecular Pharmacoloy. 1989 July; 36(1):106-112)). Ca2+ influx into cells activates a number of enzymes, including phospholipases, endonucleases, and proteases such as calpain. These enzymes go on to damage cell structures such as components of the cytoskeleton, membrane, and DNA. Normally, glutamate concentration inside the cells is 10,000 times greater than outside the cell (Teichberg, Vivian., and Vikhanski, Luba. “Protecting the Brain from a Glutamate Storm.” The DANA Foundation. Thursday, May 10, 2007). Increased extracellular glutamate levels leads to the activation of Ca2+ permeable NMDA receptors on myelin sheaths and oligodendrocytes, leaving oligodendrocytes susceptible to Ca2+ influxes and subsequent excitotoxicity (Nakamura et al, “S-nitrosylation of Drp1 links excessive mitochondrial fission to neuronal injury in neurodegeneration” Mitochondrion, 2010 August; 10(5):573-8; Dutta et al. (January 2011). “Mechanisms of neuronal dysfunction and degeneration in multiple sclerosis”. Prog Neurobiol 93 (1): 1-12). Excitotoxicity may be involved in spinal cord injury, stroke, traumatic brain injury, multiple sclerosis, Alzheimer's disease, Parkinson's disease, alcoholism, alcohol withdrawal, over-rapid benzodiazepine withdrawal, and Huntington's disease (Wikipedia, “Excitotoxicity”. March, 2012. http://en.wikipedia.org/wiki/Excitotoxicity; Kim, A. H.; Kerchner, G. A.; and Choi, D. W., “Blocking Excitotoxicity or Glutamatergic Storm.” CNS Neuroprotection. Marcoux, Chap 1. Springer, New York. 2002. pp. 3-36; Hughes, J. R., “Alcohol withdrawal seizures”. Epilepsy Behav 15 (2): 92-7) (February 2009)). Toxicity from excess glutamate is also thought to be a component of other conditions as diverse as hypoglycemia, damage to a newborns brain caused by interrupted oxygen supply during delivery, exposure to nerve gas, and is probably involved in chronic nerve damage in such conditions as glaucoma, amyotrophic lateral sclerosis, and HIV dementia (Teichberg, Vivian, and Vikhanski, Luba. “Protecting the Brain from a Glutamate Storm.” The DANA Foundation. Thursday, May 10, 2007).
Theanine is extremely safe, with a LD50 toxicity of >5000 mg/kg in humans (“L-Theanine”. www.drugs.com/npp/I-theanine.html). Theanine may protect against nerve cell damage by blocking glutamine entrance to cells due to the similarity in stereochemical structures of Theanine and glutamine. (Kakuda T, et al., “Protective effect of gamma-glutamylethylamide (Theanine) on ischemic delayed neuronal death in gerbils,” Neuroscience Letters 2000; 289(3): 189-192). GABA (Gamma-Aminobutyric Acid) is the most widespread inhibitory neurotransmitter of the brain. When GABA levels are decreased there is an augmentation of nerve impulses in the neuron. Theanine increases GABA levels in the brain, opposing excess stimulation of nerve impulses by excitatory neurotransmitters.
As such, crystal engineering and Theanine dissolution may be useful in the prevention and treatment of diseases or conditions associated with glutamate toxicity, decreased glutathione levels, decreased GABA levels, neuronal damage or death from neurotransmitter excitotoxicity, amyloid beta-induced neurotoxicity, neurotoxins and oxidative stress inducers that damage the nervous system. Theanine crosses the blood-brain barrier via leucine-preferring transport system (Yokogoshi, Hidehiko; Kobayashi, Miki; Mochizuki, Mikiko; and Terashima, Takehiko, “Effect of Theanine, r-Glutamylethylamide, on Brain Monoamines and Striatal Dopamine Release in Conscious Rats.” Neurochemical Research, May 1998, Volume 23, Issue 5, pp. 667-673). The protective effect of L-Theanine against aluminum-induced neurotoxicity was shown by Sumathi et al., 2014. The study clearly indicates the potential of L-Theanine in counteracting the damage inflicted by aluminum on rat brain regions (Sumathi, T.; Shobana, C.; Thangarajeswari, M.; Usha, R. “Protective effect of L-Theanine against aluminum-induced neurotoxicity in cerebral cortex, hippocampus and cerebellum of rat brain-histopathological, and biochemical approach.” Drug Chem Toxicol Mar. 24, 2014). Several environmental neurotoxins and oxidative stress inducers are known to damage the nervous system and are considered major factors associated with the selective vulnerability of nigral dopaminergic neurons in Parkinson's disease (Cho, H. S.; Kim S.; Lee S. Y.; Park J. A.; Kim S. J.; Chun H. S.; “Protective effect of the green tea component, L-Theanine on environmental toxins-induced neuronal cell death.” Neurotoxicology. 2008 July; 29(4):656-62). Cho et al., analyzed L-Theanine's capabilities to protect DNA in cells from environmental toxins. The researchers used the human dopaminergic cell line SH-SY5Y, and subjected the cell line to the neurotoxins rotenone and dieldrin. There were a variety of benefits found in the cell cultures that were also treated or pre-treated with L-Theanine, namely, decreased DNA fragmentation and apoptotic cell death. Yet, L-Theanine protected brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) production in the cells (Biohacks Blog, “L-Theanine Attenuates Beta-Amyloid Plaque Neurotoxicity and Neuronal Cell Death.”). The authors claim that L-Theanine directly provides neuroprotection against Parkinson's disease-related neurotoxicants and may be clinically useful for preventing Parkinson's disease symptoms (Cho, H. S.; Kim S.; Lee S. Y.; Park J. A.; Kim S. J.; Chun H. S., “Protective effect of the green tea component, L-Theanine on environmental toxins-induced neuronal cell death.” Neurotoxicology. 2008 July; 29(4):656-62). Di et al., showed that L-Theanine protects the APP (Swedish Mutation) transgenic SH-SY5Y cell against glutamate-induced excitotoxicity via inhibition of the NMDA receptor pathway (Di X., et al., “L-Theanine Projects The APP (Swedish Mutation) Transgenic SH-SY5Y Cell Against Glutamate-Induced Exitotoxicity via Inhibition of the NMDA Receptor Pathway.” Neuroscience 168 (2010) 778-786). Memantine a glutamate antagonist, decreases glutamate's effect by blocking the NMDA receptor. As well, present inventor H. G. Brittain has shown that Memantine does form a cocrystal with Theanine which may be useful in the prevention and treatment of diseases or conditions associated with glutamate toxicity. The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
A new study that identifies the cause of Alzheimer's disease, dementia, and Parkinson's disease as the breakdown in function of the tau protein in nerve cells and shows that a drug that is presently approved can reverse the memory loss associated with the diseases was reported in the Oct. 31, 2014, edition of the journal Molecular Neurodegeneration (Hamaker, Paul. “New research points to tau protein malfunction as cause of Alzheimer's.” Nov. 2, 2004). This is the first time that research has proven that the loss of tau protein function precedes the formation of beta-amyloid plaques in Alzheimer's disease. Dr. Charbel Moussa, professor of neuroscience at Georgetown University Medical Center, and colleagues made the discovery (Hamaker, Paul. “New research points to tau protein malfunction as cause of Alzheimer's.” Nov. 2, 2004). Cell death is the result of the accumulation of nonfunctional tau protein and beta-amyloid plaques in the nerve cells. The introduction of functional tau protein into nerve cells that had a loss of tau protein restored the normal nerve function. The discovery explains why some people can have beta-amyloid plaques and suffer no memory loss or nerve damage (Hamaker, Paul. “New research points to tau protein malfunction as cause of Alzheimer's.” Nov. 2, 2004). Nilotinib was found to assist in the restoration of nerve function in cells that had some tau protein in them (Hamaker, Paul. “New research points to tau protein malfunction as cause of Alzheimer's.” Nov. 2, 2004). The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
Glutathione is the liver's first-line defense against drugs and chemicals. It is used by cancer cells against drugs and chemicals. Cancer cells use glutathione to detoxify doxorubicin and escort the drug out of cells. Theanine is able to interfere with this process due to its structural similarity to glutamate. Glutamic acid, or glutamate, is one of the components of glutathione, the drug detoxifier. Because it looks like glutamic acid, cancer cells take up and mistakenly use the Theanine to create glutathione. But the glutathione they create with Theanine does not detoxify like natural glutathione. Instead, this Theanine-based glutathione appears to block the ability of cancer cells to detoxify. Further, in addition to enhancing doxorubicin's cancer-killing effects without harming healthy tissue, Theanine also keeps doxorubicin out of healthy tissue. This is a major added benefit, since one of the drawbacks of the use of doxorubicin is its toxicity to the heart. The potential of Theanine as an adjunct to cancer chemotherapy was proposed by researcher Yasuyuki Sadzuka, who confirmed that Theanine, a major amino acid in green tea, enhances the antitumor activity of doxorubicin (DOX) without an increase in DOX-induced side effects. He postulated that the action of Theanine is due to decreases in glutamate uptake via inhibition of the glutamate transporter and reduction of glutathione and DOX export from the cell. Theanine enhances the antitumor activity not only of DOX but also of cisplatin and irinotecan. In essence, Sadzuka found that Theanine could block the export of doxorubicin (Adriamycin) from cancer cells by blocking the glutamate and glutathione transporter mechanisms. The elevated level of the drug within cancer cells strongly inhibits the tumor. (Sadzuka Y, et al., “The effects of Theanine, as a novel biochemical modulator, on the antitumor activity of Adriamycin.” Cancer Letters 1996; 105(2):203-209; Sadzuka Y, et al., “Modulation of cancer chemotherapy by green tea.” Clinical Cancer Research 1998; 4(1): 153-156; Sadzuka Y, et al., “Efficacies of tea components on doxorubicin induced antitumor activity and reversal of multidrug resistance.” Toxicology Letters 2000; 114(1-3): 155-162; Sadzuka Y, et al., “Improvement of idarubicin induced antitumor activity and bone marrow suppression by Theanine, a component of tea.” Cancer Letters 2000; 158(2): 119-24; Sadzuka Y, et al., “Enhancement of the activity of doxorubicin by inhibition of glutamate transporter.” Toxicology Letters 2001; 123(2-3): 159-67; Sadzuka Y, et al., “Effect of dihydrokainate on the antitumor activity of doxorubicin.” Cancer Letters 2002; 179(2): 157-163). The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
The box jellyfish (Chironex fleckeri) live primarily in coastal waters of northern Australia and throughout the Indo-Pacific. (Box Jellyfish, Box Jellyfish Pictures, Box Jellyfish Facts. National Geographic. 1996-2014; Nation). Australian box jellyfish stings can cause acute cardiovascular collapse and death. Yanagihara and Shohet developed methods to recover venom with high specific activity, and evaluated the effects of both total venom and constituent porins at doses equivalent to lethal envenomation. Marked potassium release occurred within 5 min and hemolysis within 20 min in human red blood cells (RBC) exposed to venom or purified venom porin. (Yanagihara, A. A.; Shohet, R. V.; “Cubozoan Venom-Induced Cardiovascular Collapse Is Caused by Hyperkalemia and Prevented by Zinc Gluconate in Mice.” PLoS ONE, 2012; 7 (12)). Electron microscopy revealed abundant, 12-nm transmembrane pores in RBC exposed to purified venom porins. C57BL/6 mice injected with venom showed rapid decline in ejection fraction with progression to electromechanical dissociation and electrocardiographic findings consistent with acute hyperkalemia. (Yanagihara, A. A.; Shohet, R. V.; “Cubozoan Venom-Induced Cardiovascular Collapse Is Caused by Hyperkalemia and Prevented by Zinc Gluconate in Mice.” PLoS ONE, 2012; 7 (12)). Recognizing that porin assembly can be inhibited by zinc, Yanagihara and Shohet found that zinc gluconate inhibited potassium efflux from RBC exposed to total venom or purified porin, and prolonged survival time in mice following venom injection. These findings suggest that hyperkalemia is the critical event following Chironex fleckeri envenomation and that rapid administration of zinc could be lifesaving in human sting victims. (Yanagihara, A. A.; Shohet, R. V.; “Cubozoan Venom-Induced Cardiovascular Collapse Is Caused by Hyperkalemia and Prevented by Zinc Gluconate in Mice.” PLoS ONE, 2012; 7 (12)). Since the current box jellyfish antivenom is not very effective, there is a clear unmet need in the medical community for a novel method of improving the drug delivery of an intravenous zinc gluconate formulation utilizing crystal engineering and Theanine dissolution. The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
Malignant hyperthermia is a hypermetabolic disorder of skeletal muscle that is triggered in susceptible individuals (inherited as an autosomal dominant disorder) by several inhalation anesthetic agents (sevoflurane, desflurane, isoflurane, halothane, enflurane, and methoxyflurane) and succinylcholine. (Akif. “Malignant Hyperthermia.” Anesthesia General, Feb. 11, 2011). These anesthetic triggers cause intracellular hypercalcemia in skeletal muscle by decreasing the uptake of calcium by the sarcoplasmic reticulum. The intracellular hypercalcemia activates metabolic pathways that result in adenosine triphosphate (ATP) depletion, acidosis, membrane destruction, and ultimately cell death. (Akif. “Malignant Hyperthermia.” Anesthesia General, Feb. 11, 2011). Core body temperature may reach as high as 112° F. Possible complications of malignant hyperthermia includes amputation, rhabdomyolysis, compartment syndrome, disseminating intravascular coagulation, arrhythmias, renal failure, metabolic acidosis, respiratory acidosis, myopathy, and death. (Heller, J. L. “Malignant Hyperthermia.” Medline Plus, US National Library of Medicine, Apr. 5, 2013). If malignant hyperthermia is not recognized and treated immediately during surgery, cardiac arrest may ensue. Dantrolene sodium which acts by inhibiting the release of calcium from the sarcoplasmic reticulum is the only medication that is currently approved for the treatment of malignant hyperthermia. Application of a platform drug delivery system utilizing crystal engineering and Theanine dissolution with Dantrolene sodium is paramount, since improved drug delivery would benefit the patient and reduce or prevent the severe complications of this hypermetabolic disorder of skeletal muscle. The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
The beneficial effects of the triptans in patients with migraine are related their multiple mechanisms of actions at sites implicated in the pathophysiology of migraine. These mechanisms are mediated by 5-HT (1B/1D) receptors and include vasoconstriction of painfully dilated cerebral blood vessels, inhibition of the release of vasoactive neuropeptides by trigeminal nerves, and inhibition of nociceptive neurotransmission (Tepper, S. J.; Rapoport, A. M.; Sheftell, F. D. “Mechanisms of Action of the 5-HT 1B/1D Receptor Agonists.” Arch Neurol. 2002 July; 59(7): 1084-8). Sumatriptan is indicated for the acute treatment of migraine with or without aura in adults. It is known that large doses of sumatriptan can cause sulfhemoglobinemia, a rare condition in which the blood changes from red to greenish-black, due to the integration of sulfur into the hemoglobin molecule (Patient Bleeds Dark Green Blood.” BBC News. Jun. 8, 2007). Serious cardiac events, including some that has been fatal, have occurred following the use of sumatriptan tablets and have included ventricular tachycardia, ventricular fibrillation, coronary artery vasospasm, myocardial ischemia, and myocardial infarction (Sumatriptan—FDA Prescribing Information, Side Effects and Uses.” January 2014). Application of a platform drug delivery system utilizing crystal engineering and Theanine dissolution with sumatriptan is paramount, since improved drug delivery would improve the clinical status of the patient more rapidly, and would be expected to reduce many serious side effects associated with the use of sumatriptan. The present invention satisfies these and other medical needs and overcomes deficiencies found in the prior art.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operation advantages and specific objects attained by its uses, reference is made to the accompanying figures and descriptive matter in which a preferred embodiment of the invention is illustrated.